She's the kind of person to whom you are immediately drawn, her small stature belying her big personality and incredible strength of character. She's open, warm and bossy as she immediately puts me to work.

"Just hang up that poster there," she says, pointing to the wall where it should be, munching on a bruised banana (nothing goes to waste) as she prepares for the event to mark the launch of SAHarvest at the Sheraton Hotel in Pretoria.

The charity, in partnership with the UN Environmental Programme, is based on the OzHarvest model that Kahn, 64, founded in Australia in 2004.

OzHarvest is a "food rescue" organisation that collects quality excess food from commercial outlets and other food providers like markets and farmers and delivers it to more than 900 charities that support people in need across Australia.

It's run by volunteers and has delivered more than 60million meals and saved more than 20,000 tonnes of food from ending up in landfill.

At the Pretoria launch of the local version, chefs David Higgs from Marble and James Diack from Coobs, both in Johannesburg, joined Sheraton chef Alexandre Coupy in preparing dishes made from surplus food, either from their own restaurants or from a local butchery and the Tshwane fresh produce market.

Born in Johannesburg, Kahn left when she was 17. "It was my choice to leave," she says, sipping on a cup of rooibos tea. "I didn't give back then, so for me bringing SAHarvest to life is intrinsically connected to me doing something good right here in this country."

Asked about the enormity of the task of feeding the millions of South Africans who go to bed hungry every night, Kahn says: "It's not as simple, setting up something here, and it's going to be a challenge because the need is so great, but we must make a start, no matter how small it is."

Kahn has inspired a number of OZHarvest-style charities around the world to help reduce the dumping of food and divert it to those who need it.

"I didn't start it because I was a millionaire, I started it because I had a need to find a purpose."

Kahn says her turning point came when working in her business as an events planner.

"I was doing an event for a lady who was spending thousands of dollars on an event with a purple colour scheme, and the triviality of matching the purple font on the invitations to the purple flowers to the purple place settings - it suddenly struck me how beyond absurd it was, and that's when I knew I needed to find my values again," she says.

"What I needed to do, was to take the food to the people who needed it."

She stops, and jumps up to adjust a poster. "And, I made it happen," she added.

I ask what she would do as a "food-insecure person" if she were handed a lettuce, an onion and a loaf of bread. Without hesitating, she says she would make a soup with the onion and lettuce, and croutons with the bread. A real pro indeed.